What are hives (nettle rash)? Symptoms and treatment Email What is nettle rash (hives)? Nettle rash (also known as urticaria or hives) is composed of reddish itchy weals or swellings in the skin similar to those resulting from contact with stinging nettle. Urtica is the Latin word for nettle. The rash can vary in shape and size. It can be very itchy and usually goes away within 24 hours. Nettle rash may occur repeatedly or as a single episode. What causes nettle rash? In about 90 per cent of cases there's no apparent cause. ADVERTISEMENT - CONTINUE READING BELOW Sometimes, however, it's possible to identify the cause of the nettle rash. It most commonly appears to be because of an allergic reaction. Any of the following may trigger symptoms: a particular kind of food that causes an allergy .

Eggs, nuts, strawberries and seafood are some of the common culprits contact with pollen or fungal spores infections, which may be caused by viruses, parasites or bacteria contact with plants, such as stinging nettles contact with animals or creatures, such as stinging jellyfish physical stimuli, such as feeling cold or warm, sunlight, water, sweating or pressure substances, such as perfumes, preservatives, colourings, nickel or tar. During an allergic reaction, a chemical called histamine is released by cells in the skin. Histamine makes the blood vessels dilate and become more permeable (leaky) so that fluid seeps out into the skin. The rash itself is due to a local build up of an excessive amount of fluid in the skin (oedema). In severe cases this may be followed by swelling in other parts of the body as well. MOST POPULAR If swelling occurs around the eyes, lips, tongue, larynx, hands or genitalia – it's called angioneurotic oedema. What are the symptoms of nettle rash? Nettle rash usually starts out as an itchy spot on the skin. After a few minutes the weals develop into areas of reddish blisters of varying sizes.

The rash usually lasts for about two to three hours and can then disappear only to return in a different place. How do you differentiate between the different types of nettle rash? Nettle rash is differentiated according to the cause of the rash and whether it has appeared suddenly or represents a chronic condition, such as attacks that last for more than a month. Acute nettle rash In cases of acute nettle rash, the attack begins within an hour of exposure to the allergen, so it's often possible to work out what has caused it. Symptoms will appear every time the individual is exposed to that particular allergen. The majority of acute cases last just 24 to 48 hours and certainly not more than 6 weeks. There's usually no need to call the doctor for acute cases of nettle rash. The patient is able to find the cause of the rash and follow it up with home treatment. In more severe cases, however, it may be necessary to consult a doctor. Children and young adults are particularly prone to repeated attacks of nettle rash. Acute nettle rash can be divided into allergic and non-allergic (physical) nettle rash. Both types present immunological reactions.

It is important to know that very rarely, acute nettle rash can be the first symptom of a more serious and potentially life threatening reaction, known as anaphylaxis. This may lead to swelling of the face, hands and feet. Swelling may also affect the mouth, tongue, throat and breathing tubes, leading to wheezing and breathlessness and difficulty speaking or swaollowing. The individual affected may also feel faint and sick and complain of stomach pains and develop vomiting. ADVERTISEMENT - CONTINUE READING BELOW The overall shock to the body may cause the individual to collapse and become unconscious. Aanaphylaxis is a medical emergency and one should call 999 and request an ambulance if you think you or someone else is suffering from this condition. The ambulance control will ask you about your (or their) symptoms. Chronic nettle rash Chronic cases are, by definition, more difficult to treat and often need long-term treatment. With chronic nettle rash (when the rash lasts for more than six weeks), it's advisable to contact your GP for further advice – and if appropriate, get a referral to a skin specialist (dermatologist). Fortunately, this chronic form is uncommon.

In about 90 per cent of cases, no cause can be found for the symptoms. This kind of nettle rash is called idiopathic urticaria. In the other 10 per cent of cases, the substance (such as nickel or perfume) causing the allergy can be identified. In extremely rare cases, urticaria may be related to a more serious underlying medical condition. If a thorough examination shows that there is no apparent trigger for the chronic nettle rash, do not be alarmed. Chronic nettle rash can be treated, and in about half of all cases the rash disappears by itself within six months. But sometimes the condition may be resistant to treatment and persist for years. Hereditary angioneurotic oedema This is an inherited condition that can cause nettle rash and swelling around the eyes, mouth and hands. It requires treatment by a specialist. How does the doctor make a diagnosis? Often it's enough to tell the doctor when, where and how you got the symptoms. Skin tests, a thorough examination and blood samples can be used to confirm the diagnosis. Possible complications Disturbed sleep due to itch and irritation.

Angioneurotic oedema (swollen mucous membranes of the larynx or bronchi) that may sometimes require immediate treatment. Future prospects In acute cases: the rash usually disappears when the cause is avoided. If treatment is necessary, different medicines are available that are effective at relieving the symptoms. New medicines have been developed recently, and the prospects of successful treatment of hereditary angioneurotic oedema are good. What medication can be used? Antihistamines are the most commonly used group of medicines for nettle rash. They relieve itching, reduce nettle rash from a severe to a mild outbreak and make the rash disappear. They may be administered as tablets or injections. Antihistamines that cause drowsiness are useful at night, if one has trouble sleeping. In rare cases, treatment by a skin specialist with anti-allergy medicine may be necessary. The treatment of hereditary angioneurotic oedema must be carried out by a specialist. Steroids are commonly used to treat this condition. Other people also read: Stings and insect bites : how to treat an insect bite or sting. Scarlet fever : how does the doctor make a diagnosis?

Based on a text by Dr Flemming Andersen Last updated Urticaria (hives) - NHS Choices Urticaria (hives) Nettle-rash Treatment Introduction Urticaria – also known as hives, weals, welts or nettle rash – is a raised, itchy rash that appears on the skin. It may appear on one part of the body or be spread across large areas. The rash is usually very itchy and ranges in size from a few millimetres to the size of a hand. Although the affected area may change in appearance within 24 hours, the rash usually settles within a few days. Doctors may refer to urticaria as either: acute urticaria – if the rash clears completely within six weeks chronic urticaria – in rarer cases, where the rash persists or comes and goes for more than six weeks, often over many years A much rarer type of urticaria, known as urticaria vasculitis, can cause blood vessels inside the skin to become inflamed. In these cases, the weals last longer than 24 hours, are more painful, and can leave a bruise.

When to seek medical advice Visit your GP if your symptoms don't go away within 48 hours. You should also contact your GP if your symptoms are: severe occurring alongside other symptoms Who's affected by urticaria? Acute urticaria (also known as short-term urticaria) is a common condition, estimated to affect around one in five people at some point in their lives. Children are often affected by the condition, as well as women aged 30 to 60, and people with a history of allergies . Chronic urticaria (also known as long-term urticaria) is much less common, affecting up to five in every 1,000 people in England. What causes urticaria? Urticaria occurs when a trigger causes high levels of histamine and other chemical messengers to be released in the skin. These substances cause the blood vessels in the affected area of skin to open up (often resulting in redness or pinkness) and become leaky. This extra fluid in the tissues causes swelling and itchiness. Histamine is released for many reasons, including: Read more about the causes of urticaria .

Diagnosing urticaria Your GP will usually be able to diagnose urticaria by examining the rash. They may also ask you questions to find out what triggered your symptoms. If your GP thinks that it's caused by an allergic reaction, you may be referred to an allergy clinic for an allergy test . However, if you've had urticaria most days for more than six weeks, it's unlikely to be the result of an allergy. You may also be referred for a number of tests, including a full blood count (FBC) , to find out whether there's an underlying cause of your symptoms. Read more about diagnosing urticaria . Treating urticaria In many cases, treatment isn't needed for urticaria, because the rash often gets better within a few days. If the itchiness is causing you discomfort, antihistamines can help. Antihistamines are available over the counter at pharmacies – speak to your pharmacist for advice. A short course of steroid tablets (oral corticosteroids ) may occasionally be needed for more severe cases of urticaria. If you have persistent urticaria, you may be referred to a skin specialist (dermatologist).

Treatment usually involves medication to relieve the symptoms, while identifying and avoiding potential triggers. Read about treating urticaria . Complications of urticaria Around a quarter of people with acute urticaria and half of people with chronic urticaria also develop angioedema, which is a deeper swelling of tissues. Chronic urticaria can also be upsetting and negatively impact a person's mood and quality of life. Angioedema Angioedema is swelling in the deeper layers of a person's skin. It's often severe and is caused by a build-up of fluid. The symptoms of angioedema can affect any part of the body, but usually affect the: eyes Hives | definition of hives by Medical dictionary Hives | definition of hives by Medical dictionary Hives is an allergic skin reaction causing localized redness, swelling, and itching . Description Hives is a reaction of the body's immune system that causes areas of the skin to swell, itch, and become reddened (wheals).

When the reaction is limited to small areas of the skin, it is called "urticaria." Involvement of larger areas, such as whole sections of a limb, is called "angioedema." Causes and symptoms Causes Hives is an allergic reaction. The body's immune system is normally responsible for protection from foreign invaders. When it becomes sensitized to normally harmless substances, the resulting reaction is called an allergy. An attack of hives is set off when such a substance, called an allergen, is ingested, inhaled, or otherwise contacted. It interacts with immune cells called mast cells, which reside in the skin, airways, and digestive system. When mast cells encounter an allergen, they release histamine and other chemicals, both locally and into the bloodstream. These chemicals cause blood vessels to become more porous, allowing fluid to accumulate in tissue and leading to the swollen and reddish appearance of hives. Some of the chemicals released sensitize pain nerve endings, causing the affected area to become itchy and sensitive. A wide variety of substances may cause hives in sensitive people, including foods, drugs, and insect bites or stings.

Common culprits include: nuts, especially peanuts, walnuts, and Brazil nuts fish, mollusks, and shellfish bee, wasp, and hornet stings bites of mosquitoes, fleas, and scabies Symptoms Urticaria is characterized by redness, swelling, and itching of small areas of the skin. These patches usually grow and recede in less than a day, but may be replaced by hives in other locations. Angioedema is characterized by more diffuse swelling. Swelling of the airways may cause wheezing and respiratory distress. In severe cases, airway obstruction may occur. Diagnosis Hives are easily diagnosed by visual inspection. The cause of hives is usually apparent, but may require a careful medical history in some cases. Treatment Mild cases of hives are treated with antihistamines , such as diphenhydramine (Benadryl) or desloratadine (Clarinex). Clarinex is non-sedating, meaning it will not make patients drowsy. More severe cases may require oral corticosteroids , such as prednisone. Topical corticosteroids are not effective.

Airway swelling may require emergency injection of epinephrine (adrenaline). Alternative treatment An alternative practitioner will try to determine what allergic substance is causing the reaction and help the patient eliminate or minimize its effects. To deal with the symptoms of hives, an oatmeal bath may help to relieve itching. Chickweed (Stellaria media), applied as a poultice (crushed or chopped herbs applied directly to the skin) or added to bath water, may also help relieve itching. Several homeopathic remedies, including Urtica urens and Apis (Apis mellifica), may help relieve the itch, redness, or swelling associated with hives. Prognosis Most cases of hives clear up within one to seven days without treatment, providing the cause (allergen) is found and avoided. Prevention Preventing hives depends on avoiding the allergen causing them. Analysis of new items in the diet or new drugs taken may reveal the likely source of the reaction. Chronic hives may be aggravated by stress , caffeine, alcohol, or tobacco; avoiding these may reduce the frequency of reactions. Key terms Allergen — A substance capable of producing an immediate type of hypersensitivity, or allergy.

Wheal — A smooth, slightly elevated area on the body surface, which is redder or paler than the surrounding skin. Resources n See urticaria. Patient discussion about hives Q. What caused my hives? I woke up this morning and saw that all my back and chest are covered in hives. How did this suddenly appear? What caused it? A. Urticaria (hives) is generally an allergic reaction, or an immune response to food or some other allergen, but can also appear for other reasons, notably emotional stress. Q. I was diagnosed with chronic urticaria. What is the reason for this condition? I was diagnosed with chronic urticaria last week after more than two months of urticaria (I have more than twenty 1 dollar coin area no my trunk that are red swollen and itchy). when I was younger I had a similar reaction too a bee sting and I was treated with an adrenalin shoot. Since that one time I never suffered from this kind of symptoms till two months ago. What can be the reason for this condition? A. As was said before chronic urticaria is a symptom of many problems.

I once took NSAIDs for knee pain and I started to itch myself. It took my doctor 3 weeks to understand that I was allergic to this specific drug. I also know that tomatoes can cause me an allergic reaction. Try to think is there anything new in your life? Tell it to the GP maybe he will be able to tell you if this is the reason for your symptoms. Q. hpv Can i get pregnant A. You can get pregnant you just need to tell your doctor whats going on so he can keep an eye on the issue. Hives: MedlinePlus Medical Encyclopedia Swelling of the surface of the skin into red- or skin-colored welts (called wheals) with clearly defined edges. Wheals may get bigger, spread, and join together to form larger areas of flat, raised skin. Wheals can also change shape, disappear, and reappear within minutes or hours.You know you have hives when you press the center of a wheal, it turns white. This is called blanching. Dermatographism is a type of hives. It is caused by pressure on the skin and results in immediate hives.

Exams and Tests Your health care provider can tell if you have hives by looking at your skin. If you have a history of an allergy, the diagnosis is even clearer. Sometimes, a skin biopsy or blood tests are done to confirm that you had an allergic reaction, and to test for the substance that caused the allergic response. Treatment Treatment may not be needed if the hives are mild. They may disappear on their own. To reduce itching and swelling: Do not take hot baths or showers. Do not wear tight-fitting clothing, which can irritate the area. Your provider may suggest that you take an antihistamine such as diphenhydramine (Benadryl). Follow your provider's instructions or the package instructions about how to take the medicine. If your reaction is severe, especially if the swelling involves your throat, you may need an emergency shot of epinephrine (adrenaline) or steroids. Hives in the throat can block your airway, making it difficult to breathe. Outlook (Prognosis) Hives may be uncomfortable, but they are usually harmless and disappear on their own. In most cases, the exact cause of hives cannot be identified.

When the condition lasts longer than 6 weeks, it is called chronic hives. Often, no cause can be found. Possible Complications Anaphylaxis (a life-threatening, whole-body allergic reaction that causes breathing difficulty) Swelling in the throat can lead to life-threatening airway blockage When to Contact a Medical Professional Call 911 or your local emergency number if you have: Fainting Hives and Swelling: What is It? How to Treat It? When Should I Call the Doctor? Hives are swollen, pale red bumps, patches, or welts on the skin that appear suddenly. They can happen because of allergies or other reasons. Your doctor may call them urticaria. Hives usually itch, but they may also burn or sting. They can show up anywhere on your body, including the face, lips, tongue , throat, and ears. They range in size from a pencil eraser to a dinner plate and may join together to form larger areas known as plaques. They can last for hours or up to several days. Angioedema is different. The swelling happens under the skin , not on the surface.

It’s marked by deep swelling around the eyes and lips and sometimes of the genitals, hands, and feet. It generally lasts longer than hives, but the swelling usually goes away in less than 24 hours. It’s rare, but angioedema of the throat, tongue , or lungs can block your airways, making it hard to breathe. Causes Allergic reactions, chemicals in foods, insect stings , sunlight, and medicines can make your body release a chemical called histamine . Histamine sometimes makes blood plasma leak out of small blood vessels in the skin, causing hives or angioedema. Sometimes, doctors don’t know exactly why hives have formed. Types Acute urticaria and/or angioedema are hives or swelling lasting less than 6 weeks. The most common causes are foods, medicines, latex, and infections. Insect bites or a disease may also be responsible. The most common foods that cause hives are nuts, chocolate , fish, tomatoes, eggs, fresh berries, soy, wheat, and milk. Fresh foods cause hives more often than cooked foods. Certain food additives and preservatives may also be to blame.

Drugs that can cause hives and angioedema include aspirin and other NSAIDs (such as ibuprofen ), high blood pressure medications (such as ACE inhibitors ), and painkillers such as codeine. Chronic urticaria and/or angioedema are hives or swelling that lasts more than 6 weeks. The cause is usually harder to find than in acute cases. The causes can be similar to those of acute urticaria but can also include your immune system, chronic infections, hormonal disorders, and tumors. Physical urticaria are hives caused by direct physical stimulation of the skin -- for example, cold, heat, sunlight, vibration, pressure, sweating , and exercise . They usually happen right where the skin was affected and rarely appear anywhere else. Most appear within 1 hour after exposure. Dermatographism are hives that form after firmly stroking or scratching the skin. You may also have other forms of hives. Hereditary angioedema is painful swelling under the skin. It runs in families. Continued Diagnosis Your doctor will ask you many questions to try to find the cause of hives or angioedema. You’ll also get a checkup.

Your doctor may give you skin tests to find out if you’re allergic to something. You may get blood tests, too. Treatment Hives (urticaria). What are hives? Treatment for hives. | Patient 476 Hives are itchy red or white bumps on the skin. This itchy rash is also known as urticaria, or as nettle rash. The rash may be acute (if it comes on suddenly and does not last for long) or chronic (if the rash has lasted for six weeks or more). The rash may be triggered by an allergy, or by another factor such as heat or exercise. In most cases the rash lasts 24-48 hours and is not serious. You may not require any treatment; however, medicines called antihistamines can ease the symptoms until the rash clears. What are hives? When you have hives (urticaria), you have an itchy rash caused by tiny amounts of fluid that leak from blood vessels just under the skin surface. Hives can be classed as follows: Acute - if it develops suddenly and lasts less than six weeks. Most cases last 24-48 hours. In some cases the rash only lasts a few hours.

About 1 in 6 people will have at least one bout of hives in their lives. It can affect anyone at any age. Some people have recurring bouts of acute hives. Chronic - if it persists longer than six weeks. (Chronic means persistent or ongoing.) This is uncommon. See separate leaflet called Hives (Chronic Urticaria) for more details . This rest of this leaflet deals only with hives which are acute. What does the rash of hives look like? The rash usually appears suddenly and can affect any area of skin. Small raised areas called weals (or wheals) develop on the skin. The weals look like mild blisters and they are itchy. Each weal is white or red and is usually surrounded by a small red area of skin, which is called a flare. The weal and flare rash of hives looks similar to the rash caused by a nettle sting. The weals are commonly 1-2 cm across but can vary in size. There may be just a few but sometimes many develop over various parts of the body. Sometimes weals next to each other join together to form larger ones. The weals can be any shape but are often circular.

As a weal fades, the surrounding flare remains for a while. This makes the affected area of skin look blotchy and red. The blotches then fade gradually and the skin returns to normal. Each weal usually lasts less than 24 hours. However, as some fade away, others may appear. It can then seem as if the rash is moving around the body. The rash may appear quite dramatic if many areas of skin are suddenly affected. Are there any other symptoms? Most people with hives (acute urticaria) do not feel ill; however, the appearance of the rash and the itch can be troublesome. In some cases a condition called angio-oedema develops at the same time as hives. In this condition some fluid also leaks into deeper tissues under the skin, which causes the tissues to swell. See separate leaflet called Angio-oedema for more details : The swelling of angio-oedema can occur anywhere in the body but most commonly affects the eyelids, lips and genitals. Sometimes the tongue and throat are affected and become swollen. The swelling sometimes becomes bad enough to cause difficulty breathing. Symptoms of angio-oedema tend to last longer than urticarial weals.

It may take up to three days for the swollen areas to subside and go. A variation called vasculitic hives occurs in a small number of cases. In this condition the weals last more than 24 hours, they are often painful, may become dark red and may leave a red mark on the skin when the weal goes. Technically, this type of rash is not urticaria. What causes hives? A trigger causes cells in the skin to release chemicals such as histamine. These chemicals cause fluid to leak from tiny blood vessels under the skin surface. The fluid pools to form weals. The chemicals also cause the blood vessels to open wide (dilate) which causes the flare around the weals. The trigger is not known or identified in about half of cases. Some known triggers include: Allergies - for example: Food allergies such as allergies to nuts, strawberries, citrus fruit, egg, food additives, spices, chocolate, or shellfish. Sometimes you can develop an allergy to a food even if you have eaten it without any problem many times before. Allergies to insect bites and stings. Allergies to medicines such as penicillin, aspirin, anti-inflammatory painkillers, etc.

A viral infection such as a cold or flu can trigger an urticarial rash in some people. (You react to the virus.) A mild viral infection which causes few other symptoms is probably a common trigger of an urticarial rash that develops without an apparent cause. Skin contact with certain substances causes a local area of hives in some people - for example, chemicals, latex, cosmetics, plants, ointments, nettle stings, etc. Pine tree contact: Inducible urticaria - sometimes called physical urticaria. This is a type of hives in which a rash appears when the skin is physically stimulated. The most common is called dermatographism (dermatographia) when a rash develops over areas of skin which are firmly stroked. In other cases, an urticarial rash is caused by heat, cold, emotion, exercise, or strong sunlight. See separate leaflet called Hives (Inducible Urticaria) for more details . Are hives serious? Usually not. The rash is itchy but normally fades within a day or so and causes no harm.

Most people with hives (acute urticaria) do not feel too unwell unless they have a cold or flu that is triggering the rash. The cause of the rash is not known in more than half of cases and it is commonly a one-off event. However, hives may be more serious in the following situations: Food allergy. If a food allergy is the cause then the rash is likely to return each time you eat the particular food. This is more often a nuisance than serious. Severe allergies. People who have a severe allergic reaction to peanuts, insect stings, etc, often have an urticarial rash as one of the symptoms. This is in addition to other symptoms such as severe angio-oedema, breathing difficulties, collapse, etc. A severe allergic reaction is called anaphylaxis. But note: most people with acute urticaria feel well and do not have anaphylaxis. More related content Are any tests needed? Usually no tests are needed. The rash is very typical and is easily recognised as hives by doctors. In many cases you will know what caused the rash from the events leading up to it.

(For example if you have just been put on a new medicine, or if your skin came into contact with a nettle, or if you were stung by a bee.) In some cases it may be helpful to have some allergy tests such as skin prick tests to help determine the specific cause. Sometimes blood tests for allergies can be helpful. Occasionally, if urticarial vasculitis is suspected, a sample of the skin may be taken (a skin biopsy) for further analysis. What is the treatment for hives? Often no treatment is necessary, as the rash commonly goes within 24-48 hours. A cool bath or shower may ease the itch. Calamine lotion or menthol 1% in aqueous cream can help with itching, although if it is left on for too long the itch may come back. These can be bought without a prescription. If you can identify a trigger such as a food then it would be sensible to avoid it in the future. Antihistamine tablets can ease symptoms . Antihistamines block the action of histamine which is one of the chemicals involved in causing hives. You can get antihistamines on prescription. You can also buy them without a prescription from pharmacies.

There are several types. The pharmacist will advise. The ones most often used for hives are: Fexofenadine These types of antihistamines usually work well and do not cause drowsiness. Occasionally an older antihistamine which makes you sleepy may be useful, particularly if the itch keeps you awake at night. In this case an antihistamine such as chlorphenamine may be useful. A short course of steroid tablets is sometimes prescribed in severe cases to help reduce swelling in the skin. Usually prednisolone would be the steroid used, for a short course of a few days only. If you have a severe episode of hives then you may be referred to a specialist. Skin specialists (called dermatologists) or allergy specialists (called immunologists) may be able to help. In particular, if angio-oedema or anaphylaxis occurred at the same time, you would be referred or admitted to hospital. This is to reverse the reaction quickly. It is also to confirm the diagnosis and, where possible, to identify a cause. For example, if a nut allergy is suspected to have caused a severe episode then this can confirmed by tests.

You may then be given advice on how to avoid the cause and on what to do if it should occur again. Further help & information Definition of Hives Our Hives (Urticaria & Angioedema) Main Article provides a comprehensive look at the who, what, when and how of Hives (Urticaria & Angioedema) Definition of Hives Nasal Allergy Relief Products Slideshow Hives: A raised, itchy area of skin that may be a sign of an allergic reaction. It can be rounded or flat-topped but is always elevated above the surrounding skin. It reflects circumscribed dermal edema (local swelling of the skin). The hives are usually well circumscribed but may be coalescent and will blanch with pressure. A single spot is almost always gone by 24 hours but the process may stay for weeks to months. Approximately 20% of the population has experienced a bout of hives. The hives are also called urticaria.

Last Editorial Review: 5/13/2016 Picture of Hives (urticaria) Next Urticaria, also known as hives , is an outbreak of swollen, pale red bumps or plaques (wheals) on the skin that appear suddenly -- either as a result of the body's adverse reaction to certain allergens, or for unknown reasons. Hives usually cause itching , but may also burn or sting. They can appear anywhere on the body, including the face, lips, tongue, throat, or ears. Hives vary in size (from a pencil eraser to a dinner plate), and may join together to form larger areas known as plaques. They can last for hours, or up to one day before fading. Read more about hives (urticaria and angioedema) . What are hives? What is urticaria? What causes hives? - Medical News Today What are hives? What is urticaria? What causes hives? Written by Christian Nordqvist 4 172 38 Hives are also known as urticaria, welts, wheals, or nettle rash.

It is a red, raised, itchy skin rash that is sometimes triggered by something that produces an allergic reaction - an allergen. When there is an allergic reaction the body releases a protein called histamine. When histamine is released our capillaries (tiny blood vessels) leak fluid. The fluid accumulates in the skin and causes a rash. Urticaria can be triggered by: Certain foods. Insect bites and stings. Contact with an irritant, such as nettles, chemicals or latex. Certain medications - such as NSAIDs (nonsteroidal anti-inflammatory drugs), used to treat pain, ACE inhibitors, used to treat hypertension ( high blood pressure ). Extremes of temperatures. Sunlight. Water on the skin. Experts say that in about half of all cases of urticaria the cause is never found. According to the National Health Service (NHS), UK, about 1 in every 6 people will suffer from urticaria at some time in their life. Children and women are more commonly affected than adult men. Urticaria is not contagious - you cannot pass it on to another person.

Acute urticaria or Acute hives When symptoms last less than 6 weeks it is called acute urticaria. This is by far the most common type. 25% of people with acute urticaria also have angioedema - swelling in the deeper layers of skin. Chronic urticaria or Chronic hives If symptoms of urticaria continue for more than six weeks it is called chronic urticaria. Dermatologists say that about 1 in every 1,000 people suffers from chronic urticaria. Experts are not completely sure what the causes of chronic urticaria are. However, most agree that it is closely linked with our immune system. In some cases, chronic hives may be related to an underlying autoimmune disorder, such as thyroid disease or lupus . 50% of people with chronic urticaria also have angioedema. Angioedema is similar to urticaria, but occurs deeper inside the skin. The swelling causes a burning sensation and typically occurs on the face and neck, fingers, toes, and in the genitals of males. What are the symptoms of urticaria (hives)?

Swellings, known as wheals, appear on the skin as a rash. They are usually pink or red and have an oval or round shape, and range from a few millimeters in diameter to a several inches. They can be extremely itchy. The wheals may be surrounded by a red flare. The wheals usually occur in batches, and frequently appear on the face or the extremities (arms, hands, fingers, legs, feet, and toes). In most cases a welt will disappear after a few hours, but me be replaced by new ones. They can appear on just one part of the body, or several parts. In the majority of cases symptoms are present for no more than 8 to 12 hours, and rarely continue for more than 24 hours. However, with some patients the problems may continue for quite a few days, and even several months. Anaphylaxis Anaphylaxis is a severe allergic reaction. The patient can have serious breathing difficulties, and can even lose consciousness and die if not treated quickly. The allergic reaction may involve the whole body. Anaphylaxis is a medical emergency.

If somebody has urticaria it is important to be alert for further symptoms which could indicate an anaphylaxis reaction. Anybody who experiences the symptoms listed below should call the emergency services immediately: Nausea and vomiting. An unexpectedly abrupt feeling of intense anxiety . What are the causes of urticaria (hives)? Experts say that urticaria occurs when the body releases histamine and other chemicals from under the surface of the skin. The histamine and chemicals cause inflammation and fluid to accumulate under the skin, causing wheals. In about 50% of all acute urticaria cases the trigger is unknown. The following are examples of some known triggers: Medications - including NSAIDs, such as aspirin and antibiotics . Foods - several different types of foods have been known to trigger urticaria. The most common ones are nuts, chocolate, some citrus fruits, shellfish, food additives, eggs, and wheat products. Some chemicals. Chronic illness - such as thyroid disease or lupus. Chronic urticaria (long term urticaria), on the other hand, is hardly ever caused by these triggers.

Chronic urticaria generally starts as an autoimmune response in which certain cells (mast cells) cause the release of histamine and various chemicals to be released under the skin, causing tiny blood vessels to leak, which results in swelling and wheals. Experts do not know why this happens. How is urticaria diagnosed? Acute urticaria diagnosis A GP (general practitioner, primary care physician) can easily diagnose acute urticaria by examining the rash on the skin. The doctor will attempt to find out what the trigger was, as this may help the patient prevent recurrences. Typically, the doctor will ask the patient the following questions: When the episode began. Where the episode began. Whether the patient lives or works in a place where potential triggers may exist, such as latex gloves, chemicals, or animals. What medications the patient has been taking, including herbal supplements. The patient's medical history. Whether the patient had been bitten by an insect. Whether any close relatives also have/had urticaria. In half of all cases the doctor and patient will never find out what the trigger was. However, most cases will resolve themselves within a few days and never recur.

If a doctor believes there may be a trigger which is causing an allergic reaction the patient may be referred to an allergy clinic (UK). Allergy clinics test the patient's blood and skin to find out whether there is an allergy to specific substances, such as chemicals, dust mites, or some food. Chronic urticaria diagnosis If the urticaria continues for more than six weeks the likelihood of there being some external trigger is extremely small; which is why allergy tests are not recommended. Nevertheless, the GP will be interested in factors which may exacerbate the existing urticaria, such as alcohol, caffeine intake, mental health (stress), etc. If there are any underlying causes for the chronic urticaria the doctor may order the following tests: A blood test to find out whether the patient is suffering from anemia . A stool sample to check for parasites. ESR (erythrocyte sedimentation rate) test - this can identify problems with the patient's immune system. Thyroid function test - this identifies either hyperthyroidism (overactive thyroid) or hypothyroidism (underactive thyroid). Liver function tests - these can identify whether the patient has any liver problems. What is the treatment for urticaria?

Allergic skin disorders, such as urticaria and atopic dermatitis, can cause much discomfort, have an impact on quality of life, and can sometimes cause serious complications. Like other allergic conditions, these disorders can often be effectively treated , according to the American College of Allergy, Asthma and Immunology. Acute urticaria treatment Generally, no treatment is needed for acute urticaria because symptoms are usually mild and the condition is short-lived and rarely recurs. Antihistamines - However, if symptoms are more severe, or if the condition persists the patient may be given antihistamines. Antihistamines block the effects of histamines and reduce the rash and stop the itching. Current antihistamines do not make most patients drowsy. Unfortunately, some patients may be affected and should check how they react to the antihistamine before operating heavy machinery or driving a car. Antihistamines often cause drowsiness if the patient has alcohol in his/her system. Some patients may benefit from antihistamines that do cause drowsiness, especially if the itchiness is causing sleep problems. Pregnant women should not take antihistamines, unless the GP prescribes it.

Very occasionally GPs may prescribe an antihistamine called chlorphenamine for pregnant women if it is felt the benefits are greater than the risks. In the UK thousands of pregnant women have taken chlorphenamine, and so far there have been no reports of any harmful effects to the unborn baby. Corticosteroids - If symptoms are very severe the doctor may prescribe a short course of high-dose oral corticosteroids, which suppress the immune system which usually results in either eliminating or reducing the symptoms of urticaria. Corticosteroids should not be taken for more than 5 days. The longer a patient takes Corticosteroids the greater his risks are of getting an infection. Chronic urticaria treatment Patients with chronic urticaria will have treatment which is aimed at controlling symptoms and avoiding triggers that may make them worse. Patients who have chronic urticaria and angioedema should be referred to an immunologist, an allergist or a dermatologist (skin specialist doctor). Angioedema can cause breathing difficulties which can potentially cause serious problems. Patients who only have chronic urticaria and nothing else, but whose symptoms are still severe should also be referred to a specialist.

Antihistamines - antihistamines can treat the symptoms of chronic urticaria. If symptoms are causing sleep problems the patient may benefit from also taking the antihistamines that cause drowsiness. Menthol cream - this has been shown to be a useful alternative or addition to antihistamines for patients with itchiness. Corticosteroids - these may be prescribed for chronic urticaria patients whose symptoms are more severe. Avoiding triggers - as triggers can make the existing urticaria worse, it is important for the patient to identify these triggers and avoid them. Remember, that with chronic urticaria the triggers do not cause the condition, but they can make it worse. The patient may have to abstain from consuming alcohol, or cut down consumption. He/she may have to avoid certain medications as well. Avoiding stress may help - however, this may not be easy, especially if the symptoms are affecting the patient's quality of life. Some soaps may be making symptoms worse, as well as skin creams and detergents. Meditation or hypnosis - relaxation techniques, such as medication or hypnosis have been found to help reduce symptoms and levels of stress in severely affected patients.

Diet - many patients swear that certain foods make their symptoms worse. This is a controversial subject in which experts seem to have different opinions. The following foods are known to trigger histamine production - spinach, fish, yoghurt, fish, tomato, processed, meats, chocolate, and strawberries. What are the complications of urticaria? Acute urticaria complications Approximately one quarter of all patients with acute urticaria also develop acute angioedema, which should resolve itself within about three days. Patients who have breathing problems should call the emergency services immediately. Angioedema is treated with antihistamines and oral corticosteroids. Chronic urticaria complications About half of all chronic urticaria patients will get better within 3 to 5 years. One quarter of all patients will continue having symptoms for over 10 years. As with any chronic condition, the patient can become frustrated and distressed. Approximately 15% of chronic urticaria patients report feelings of depression . Patients with symptoms of depression should inform their doctor. Depression is treatable. Written by Christian Nordqvist

Question: What is the medical name for the allergy of the skin known commonly as nettle rash or hives?
Answer: URTICARIA